PARIS (Reuters) - Far-right National Front presidential candidate Marine Le Pen, who is campaigning on a platform of economic nationalism, says France's GDP growth would accelerate to 2.5 percent towards the end of her first term if she wins the upcoming election.

Le Pen wants to drop the euro currency, a move that would throw the future of the European single currency into doubt, and vows to re-negotiate France's relationship with the European Union, promising a referendum on EU membership if those talks fail.

In an interview with newspaper Ouest-France, Le Pen described her 2.5 percent growth forecast by 2021 as "extremely reasonable".

"From the moment I implement intelligent protectionism that will fight against unfair international competition, it will turn the economy around," Le Pen was quoted as saying, adding that growth will be accompanied by an increase in purchasing power.

France's economy, the second biggest in the euro zone, has not expanded at that rate since 2004. Hobbled by heavy regulation and high unemployment, French GDP growth in 2016 was an anaemic 1.1 percent and is predicted to reach 1.5 percent this year.

Le Pen portrays herself as the champion of French workers, promising to protect them from what she has called "anarchic globalisation".

Among her policy pledges is a tax on French companies that hire foreign workers and a requirement that retailers stock a certain percentage of French products.

Le Pen also said in the interview that France would have the backing of member states including Italy, Spain, Portugal and Greece when she re-negotiates EU treaties.

The leader of the anti-immigration, eurosceptic party said EU members were suffering under the weight of Brussels bureaucracy.

Opinion polls project Le Pen winning the first round of voting on April 23 but losing in the second round a fortnight later, most likely to independent challenger Emmanuel Macron, a former economy minister under outgoing President Francois Hollande.